How CCD works 15 points.

Basic Details of a CCD can be found here. A CCD is a light bucket that can analyze photons through something called the photoelectric effect. We can thank Einstein for this understanding....

Your goal today is to learn more about the photoelectric effect by working on the lab design here

Summarize your findings on your blog for this lab. Tables of data would be nice.

Using the Sloan Digital Sky Survey LAB--25 pts

SDSS is an ambitious project that attempts to map 1/4 of the visible sky over a period of years. This is a HUGE database of more than 90 million objects.

To familiarize yourself with such a tool, you will be doing an online lab, found here

The accompanying worksheet can be found here Copy it into a Microsoft Word document if you wish, or print it off and write in the values.

Everyone must do this post, even if not enrolled in the lab section of astronomy.

Due Date: 10/7/2008

Wilson and Penzias vs. Davis and Bahcall

It's not fair! Wilson and Penzias discovered CMB in months, while Davis and Bahcall had to work almost 40 years to get their results on the neutrino.

Comment on the role of serendipity in the role of science. Do you think serendipity played a part in the discoveries of either team?

Also, comment on the fact that three of the four above won Nobel prizes. Do Nobel prizes favor experimentalists or theorists? Who gets left out?

Finding out about Sunspots LAB (30 pts)

Sunspots


How do sunspots affect us? What do you know about sunspots? Want to observe sunspots? Track solar flare/sunspot activity?m Interpret Maunder diagrams? Look at magnetic fields of sunspots?


Here's your chance. You have one week to take a look at sunspots and create an artifact and 1 page summary. Talk to me if you have questions.

How do you study? (10)

There will be a test next week, and the first two tests have not gone so well for many of you. Perhaps it is a college test that creates anxiety. Perhaps it is a lack of studying. Perhaps it is not knowing WHAT to study.

SO please, tell me by Friday noon, 9/26/2008, exactly how you prepare for the exam. Post as a COMMENT on this blog. Late assignments for the post will not be accepted.

Telescope Types (15)

As we study ideas like the HR diagram, we need more and more telescopes to gather data. How do new telescopes, like the Webb telescopes, which focus on gathering light from ancient stars, differ from Galileo's or Newton's, or even the Hale telescope? What types of EM radiation do they look for? Why can't we see these from earth?

Pick one of the following telescopes and find out a)the EM radiation range targeted by the following telescopes (there may be more than one) b) a picture generated by this telescope (or, if it is a prototype, a schematic of the design) c) how old the light coming into the telescope is, in light years or light minutes d) if the telescope uses mirrors, CCDs, lenses, or a combination of all. Post. Note: this is such an open-ended assignment that it would be INCONCEIVABLE for all the data to be the same (so quit copying..I notice :-)


Chandra

James Webb Telescope

Hubble

Spitzer

SOHO

the Very Large Array

Notes on Stellar Spectra (10 pts)

The picture includes some of the notes that the class took on stars and stellar spectra. Use the class-generated information to answer the questions below. Do this on your own blog, please.

1. Absorption spectra are created when a gas passes in front of an emitted photon of light. A line spectra appears when no gas is available. What type of spectra are more likely to be produced when light travels to earth?

2. Is parallax more likely to appear for closer or further stars? Why do you believe this?

3. A Cepheid variable is a star that allows us to measure distance using a period? What variable are we using for the period?

4. What is the the nuclear engine in the heart of a star, and how does it work?

5. How is magnitude different from a star's intensity? Why?

Escaping the sun LAB/class data (25 pts)

Go to CLEA and get the lab from here

Login and turn the layers ON for at least one trial for each Part.

Part A: Run the flow situation for a photon. Record the data in terms of # of layers vs. interactions. Collect data for 5, 10, 15, 20, and 25 layers

As the number of layers increases, what happens to the number of interactions? Is this a linear relationship, or an exponential relationship? How do you know?

Part B: Run the flow situation for a diffusion, and record the data as you did in Part A.

How did the data change when we had larger numbers of photons? Is this data more accurate or less accurate than that collected in Part A? Why do you think so?

Part C: Run the EXPERIMENT. The red cylinder represents the atmosphere, the line drawing at the right represents your eye, and the light at the left represents a photon leaving the light source.

Collect data for photons at 1.5 eV, 1.8 eV, 2.0 eV, 2.3 eV and 2.5 eV. Notice as you adjust the energy, you also adjust the wavelength.

Create a table as follows:

Energy (ev) Wavelength (nm) Photons sent Photons detected



As the energy of a photon increases, what happens to its wavelength? As the energy of a photon increases, what pattern is present for the number of photons detected? Why?


Part D: Run the EXPERIMENT again, but this time, set the photon energy level at 2.2 eV, and change the gas the element is traveling through.

This time, your table should look like this:

Energy (eV) Wavelength (nm) Gas Atoms Photons Sent Photons Detected

What effect do the different types of gas atoms have on the # of photons detected? What would this have to do with a line spectra? If you changed the energy of the photons and ran the experiment again and again, do you think you would continually get the same patterns? Why or why not?


This lab/class activity is due as a post on your blog on 9/24/2008.

Savage Sun

This is a required video for the class. Please highlight notes as you do this.

Annie Cannon and the Spectra 10 points

Imagine you have one task to which you spend your ENTIRE life in dedication. What would you do? Annie Cannon chose to spend her life studying spectra, and a biography appears here

Your blog post today tells me of your biggest dream or passion at this point in your life....who knows, maybe you will be remembered for more than 400000 contributions, as she was...

Lab 4: Measuring the Speed of Light with Chocolate

Measuring the Speed of Light With Chocolate (15 points, 20 if you vlog the activity)


Total Duration:
20 minutes
Materials and Equipment:
1. Microwave
2. Chocolate chips or a big bar of chocolate--the cooking size.
3. Paper plate
4. Ruler

Procedures:
Remove turntable from microwave
Scatter a single layer of chocolate chips over paper plate, or use a big bar of chocolate.
Place in microwave
Microwave for a few seconds (depends on microwave--15 to 45 seconds) until chocolate starts to melt
Measure the distance between hotspots



Measuring the Speed of Light with Chocolate
(adapted from apps.caes.uga.edu/sbof/main/lessonPlan/MeasuringSpeedLightChocolate.pdf )

Anyone can measure the speed of light (c) - with chocolate and a microwave
oven! The only equipment you need for this experiment is a microwave, a ruler
and chocolate.

The speed of light is equal to the wavelength (λ) multiplied by the frequency (f)
of an electromagnetic wave (microwaves and visible light are both examples of
electromagnetic waves).

c=λ*f

When you turn on your microwave oven, electrical circuits inside start generating
microwaves – electromagnetic waves with frequencies around 2.5 gigahertz –
2500000000 Hz. These waves bounce back and forth between the walls of the
oven. The size of the oven is chosen so that the peaks and troughs of the
reflected waves line up with the incoming waves and form a “standing wave”.
The electromagnetic field inside the microwave behaves in roughly the same way
as a guitar string except the vibrations are in “the electromagnetic field”. Where
the vibrations are greatest (the antinodes), you will see the greatest heating, but
at the nodes, the chocolate will only melt slowly as heat diffuses into those
areas.


You do it.
Remove the turntable from the microwave (so the plate does not rotate). Place
chocolate scattered on a plate inside the microwave. Heat the chocolate until it
just starts to melt - about 20 seconds. There will be some melted hot spots and
some cold spots in the chocolate.
The distance between the melted areas is half the wavelength of the microwaves
or the distance between the antinodes. So, from this simple experiment, and
some easy math, you can work out the speed of light!
c=2*x*f
Distance between the hot spots ______________________________cm
Wavelength _____________________________________________cm
Wavelength _____________________________________________m
Frequency of the microwave ________________________________m
EQUATION _____________________________________________
Your calculated speed of light _______________________________m/s

Electromagnetic Radiation

Think of an technological application of electromagnetic radiation in your life today and explain how your life would be different without it. This should be a post on your own blog.

What is up with Mercury? Lab 3 (10 pts)

Look up the rotation rate and the revolution rate of Mercury at nineplanets.org What happened in the lab we did with class? What does it mean for the a) rotation rate of mars? b) the intensity of radio waves over time? c) the meaning of the five slices of data we got back over time? Post your answer in your blog...

What is it? (10 pts)

Click here for an alternative to the UFO explanation.

What is YOUR opinion on the Tunguska explosion? Meteor, comet, nuclear blast? Place a post on your blog, with three pieces of evidence to support your rationale.

Why Does a Magnet Matter (10 pts)

The earth contains a giant magnet. Van Allen pointed this out, discovering the radiation belts for which he is famous. This leads to the auroras, or Northern and Southern lights.

Watch the clip and give 3 pieces of evidence for the earth experiencing magnetic reversal. Also explain why the earth as a magnet is such an important feature. You may do this in your blog or here, in the comments section.

Reflecting vs. Refracting Telescope (10 pts)

Compare Newton's telescope to Galileo's telescope, and then answer the following on the comments section of this blog.

What advantages did Newton's telescope have over Galileo's?
Why were people afraid Galileo's telescope was a 'blasphemy'?
What impact did the telescope have on our society? List three advantages that occurred as a result of the improvement.

The Moons of Jupiter: Astro Lab 2 (20 points)

Did you know that Jupiter has 63 moons? You need to know about4 ofthem by doing the activity found at CLEA on a Windows-based machine.

Go to here and download Juplab.exe. Track the progress of the 4 moons of Jupiter of 30 days, and then graph the patterns generated. Hand these in, after answering the following questions:

a) what patterns are observed, and what does that suggest?
b) why did Galileo see this as a 'mini-solar system'
c) what is so special about Io?
d) how do your findings relate to Kepler's laws?

Please make a comment on the COMMENTS section of this blog post, rather than your own.

Scaling the Solar System (10 points)

Today, you will use the part of the solar system you chose yesterday and create a new personal blog post. If you chose a part of the solar system not mentioned on the sites given, assume you are on Mars, instead.

Go to: http://www.exploratorium.edu/ronh/solar_system/

http://www.exploratorium.edu/ronh/age/index.html

http://www.exploratorium.edu/ronh/weight/index.html

Now, answer the following questions:

a) If the solar system was the length of the hallway between my room and guidance, and the Sun was in my room, where would Earth be located? What about your solar system feature? Why do you believe this?

b) If you were three years old on your planet, how old would you be on Earth? Why the difference?

c) If you weighed 200 lbs on earth, how much would you weigh on your planet? Which planet in the solar system would make you the heaviest? Why does this matter?

One Great Part of the Solar System

Find a YouTube or other video clip that describes your planetary features. Watch it. Embed it into your blog.

Summarize your top five facts from the adventure in your blog post. (15 points)